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Saturday 30 November 2013

Science or storytelling? II

We are all Martians now, revisited

Eberswalde Crater
possible ancient water site/NASA
Conditions on Mars were better billions of years ago, so life could have accidentally come from there, a major international conference has been told.
Steven Benner, chemist at the Westheimer Institute for Science and Technology admits that the chances of life accidentally forming on Earth are poor because, according to a BBC News account,
The molecules that combined to form genetic material are far more complex than the primordial “pre-biotic” soup of organic (carbon-based) chemicals thought to have existed on the Earth more than three billion years ago, and RNA (ribonucleic acid) is thought to have been the first of them to appear.
Simply adding energy such as heat or light to the more basic organic molecules in the “soup” does not generate RNA. Instead, it generates tar.
(Remember this for when someone tells you that’s all it took.) He thinks there might have been a better chance on Mars:
The minerals most effective at templating RNA would have dissolved in the oceans of the early Earth, but would have been more abundant on Mars, according to Prof Benner.
He suggests that elements such as boron and molybdenum, “key in assembling atoms into life-forming molecules,” came to Earth via meteorites from Mars:
“The evidence seems to be building that we are actually all Martians; that life started on Mars and came to Earth on a rock,” he commented.
Well, evidence for something is building.
“This isn’t really evidence that life came from Mars, but it is evidence that Steven Benner is very clever,” astrobiologist David Grinspoon told NBC.
Doubtless, Benner is clever.
But how clever do you have to be to sell people a product they very much want to buy? Origin of life researchers are at an impasse and willing to consider any thesis, including pure storytelling. Benner again:
“It’s lucky that we ended up here, nevertheless – as certainly Earth has been the better of the two planets for sustaining life. If our hypothetical Martian ancestors had remained on Mars, there may not have been a story to tell.”
But there sure are stories now. Grinspoon again:
“I think chemists always think they know more than they know, because nature has a lot of possible pathways it can try,” Grinspoon said.
Okay, who exactly is “nature”? Someone who “can try” to produce life? Is that like “god” in lower case? And “a lot of possible pathways” is hardly what we are looking for. Except insofar as they produce research grant and interesting conferences and news stories. Heck, it’s interesting. But it’s a bit much to call it serious science

2)“Impossible” for life to start on Earth? Thus, panspermia theory gains new traction?

Not, it seems, from fresh evidence but from fresh frustration, according to this National Geographic News article:
A long-debated and often-dismissed theory known as “panspermia” got new life in the past week, as two scientists separately proposed that early Earth lacked some chemicals essential to forming life, while early Mars likely had them.

“Basically, we went looking on Mars because the origins-of-life options on Earth just aren’t looking very good,” Benner said.
(We have covered Benner’s hypothesis that the elements boron and molybdenum from Mars were key player here. )
The reemergence of the theory of panspermia is intertwined with progress (or lack of progress) in a long-term scientific quest to find out how life began on Earth, a question that synthetic biology experts such as Benner have been working on for decades. Despite some advances, the field has come up against chemical walls that are proving impossible to climb.
Well, the problem is that the fact that origin of life is considered impossible on Earth doesn’t add to the possibility that it arose on Mars. Some faint suggestions that a Mars origin have been advanced, but Benner adds,
“A panspermia solution, after all, produces another panspermia problem,” he said. “If a Martian microbe did make it from Mars to Earth, maybe it would be as if it landed in Eden. But just as likely, it would quickly die.”
Now that he mentions it, there is little reason to expect life from Mars to just accidentally take root in a quite different atmosphere unless design can be factored in. That is why atheists such as Fred Hoyle and Francis Crick toyed with the idea that intelligent aliens were involved. They understood the problems better than their detractors.
Here’s Steve Benner arguing for Mars:

 

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